This question and its answers list the names of bike parts and cycling concepts.

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Also, I made this a community wiki, so that anyone will be able to edit it, and to stop rep-hoarding

There's a handy reference at the Park Tool Co. website, a bike repair map; it's a diagram of a bike with all the parts labeled, and is very handy! At the moment, the diagram is up at parktool.com/blog/repair-help. (They've changed the URL in the past, so this link may break.)

Edit: This page is meant to identify what things or concepts are (as per this thread in meta). If you want to recommend an accessory or a specific product you've found handy, please use the accessories page.

56 Answers
56

Bicycle Shaped Object: A derogatory term for a very cheaply produced bike aleged to have very low quality components which can break when attempting to adjust them:

For instance the BSO pictured is being sold in the UK by ASDA (owned by Walmart) for £75. These bikes tend to be mass produced and sold in flat pack boxes which must be assembled.

As purchasers in this market may often be inexperienced or ignorant, many BSOs carry features which are included for marketing purposes but are unnecessary for the typical end-user. Such features may include front and rear suspension, wide off-road style tyres and an excessive number of gear ratios. Their inclusion reduces the budget available for other components and may not increase the BSO's functionality.

It is more advisable to search for a cheap second-hand bike in a similar price range from a more experienced cyclist or on eBay than to go for one of these.

Presta Valve / Presta Tube

aka Sclaverand valve or French valve

The Presta valve is a valve commonly found in high pressure road style and many mountain bicycle inner tubes. The air pressure in an inflated tire holds the inner valve body shut. A small screw and captive nut on the top of the valve body permits the valve to be screwed shut and ensure that it remains tightly closed. The nut must be unscrewed to permit airflow in either direction (this must be done before attaching a pump). The screw remains captive on the valve body even when unscrewed fully; it is tightened again after the tire is inflated and the pump removed.

A Presta valve adapter can be used to fill a Presta tube with a normal Schrader-style air pump, although many pumps today come with a built-in adapter. These adapters can be purchased at almost any bike shop.

Door Zone

Cycling in the Door Zone reduces your ability to react to hazards emerging from the space between parked vehicles. These may include unobservant pedestrians, inadequately restrained dogs (whose leads can reduce your options), sports equipment and children chasing sports equipment.

Drivers entering the road from a driveway, forecourt or junction are less likely to observe a cyclist who is not occupying the space where oncoming motor vehicles are expected to be observed. This contributes to the SMIDSY(Sorry mate, I didn't see you) phenomenon.

Clipless pedals

AKA clip-in or step-in

Clipless pedals are pedals that require a special cleated cycling shoe that locks the shoe into the pedal. Clipless refers to the pedal not having a toe clip. There are two major kind of clipless pedals, LOOK and Shimano Pedaling Dynamics (SPD). To release clipless pedals, the rider typically twists his/her foot.

Toe Clips

Clipless pedals are called clipless - even though you do clip onto them - because avoid the need for toe clips and straps.

LOOK Pedals

LOOK pedals came first and were inspired by ski bindings. LOOK pedals are commonly used on road bikes. A similar (but not compatible) pedal system is Shimano's SPD-SL system.

SPD Pedals

Shimano Pedaling Dynamics or SPD pedals use a cleat that is recessed into the shoe. This allows the rider to walk normally, which is why this pedal is commonly used with mountain bikes, where the rider may have to walk short distances over some obstacles. Note that Shimano's SPD-SL system is not compatible with SPD.

Fixed-Gear

AKA: Fixie

A fixed-gear bike has the rear gear locked to the hub, which fixes the pedals rotation to the rear wheels rotation. In other words, you can't coast; the pedals are always in motion as long as the bike is. Track bikes are commonly fixed-gear.

The sprocket is screwed directly onto a fixed hub. When the rear wheel turns, the pedals turn in the same direction. This allows a cyclist to stop without using a brake, by resisting the rotation of the cranks, and also to ride in reverse.

Fixed-gear bikes are almost always single-speed (i.e. have only a single gear ratio), but internal-gear hubs without freewheels do exist.

One should note that typically, horizontal dropouts are required to convert a bike from derailleur to fixed gear, since a pulley cannot be used as a chain tensioner (when you resist to brake, the pulley will be sheared off the bike). Vertical dropouts can be adopted in some cases using something like White Industries' Eccentric Rear Hub or an eccentric bottom bracket or something.
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BatmanMar 17 '14 at 6:53

Cadence

Cadence is the number of revolutions of the crank per minute.

Cyclists typically have a preferred cadence at which they feel most comfortable, and on bicycles with many gears it is possible to stick to a favourite cadence at a wide range of speeds. Recreational and utility cyclists typically cycle around 60–80 rpm; racing cyclists around 80–120 rpm and sprinters up to 170 rpm for short bursts. The professional racing cyclist and Tour de France champion Lance Armstrong is known for his technique of keeping up high cadences of around 110 rpm for hours on end to improve efficiency1

Cadence is critical to enjoying your cycling and if you become involved in cycle racing, winning. Cadence is something that is learned and once learned you promptly forget about it and move onto getting other things right :)

For a beginner:

Get to know your gears.

Drop it into a high gear (big chainring on the front, small cog on the back)

Feel how hard it is to push (Pay attention to where you feel the muscles working)

Drop it into a low gear (smallest chainring on the front, largest cog on the back)

Feel how free your legs spin (Pay attention to how you bounce in the saddle :) If you are bouncing, then you are spinning too much, i.e. your cadence is too high)

Find a combination of gears that allow you to spin your pedals without feeling undue pain in your muscles and doesn't make you feel out of breath. (Ignore the speed for the moment)

Get to know this "sweet spot", ride around in this gear for a while and adjust your gears to suit your speed so that you balance not being out of breath and over exertion. (Watch out for the bounce in the saddle :) )

The next thing to take into account is how fast you want to go

Without a bike computer? - Your feeling of relative speed is good enough

With a bike computer? - Set a reasonable target, say 20 km/h

Using the gears you have selected for your sweet spot, try to hit your target speed.

Once you hit it, can you keep it going? For how long? - Set a reasonable target say 5 mins.

When you have finished this, where does it hurt?

In your chest? Out of breath big time? - You may have been spinning too much, i.e. your cadence was too high?

Muscles in the small of your back, quads, glutes, knees, calves groaning or hurting (not burning, burning isn't as bad as you think) - You may have been spinning too little i.e. your cadence was too low?

There is an ideal cadence proposed by some sports physiologists that is somewhere between 80 to 100 turns of the pedal per minute (rpm)

The only way to know your cadence accurately is to have a cadence enabled bike computer and sensor.

For example, You are riding your bike, it has a wheel of size 700c/29 and a tyre that is 23 mm wide, with a front chainring of 34 teeth, a rear cog of 17 and you are pedalling at a speed of 20 km/h. You should then have a cadence of 79 rpm. Simples :) (Get the bike computer ;) )

Get used to spinning your legs in that range of RPM, i.e. 80 to 100 rpm.

In all conditions, on any terrain, whatever the occasion.

It trains your heart and body to be cardio fit and with a stronger heart comes better stamina and greater strength.

Pick up the pace and work to get the legs spinning at the next level of speed.

Hard work and worth it.

Go cycling with a group more experienced than you

Watch them as they cycle, see all of the different styles and high cadence

Listen to the experienced guys as they can advise on many many things.

We're really not here to copy and paste from Wikipedia. Are there recommended cadence rates for beginners? What users are generally concerned with cadence? Perhaps you could address concerns like these?
–
Neil FeinSep 2 '10 at 23:11

2

I'm not sure that citing Lance Armstrong as an example is really useful, given that he achieved his performances through doping...
–
macApr 26 '14 at 19:53

Schrader valve/Schrader tube

aka "American valve" or "car valve"

The Schrader valve consists of a valve stem into which a valve core is threaded, and is used on virtually all automobile tires and most wider rimmed bicycle tires. The valve core is a poppet valve assisted by a spring.

A valve cap is important on a Schrader valve because if one is not fitted, dirt and water can enter the outside of the valve, potentially jamming it or contaminating the sealing surfaces and causing a leak. Rock salt and other chemical deicers used in the winter are especially damaging for the brass components in the Schrader valve.

Schrader valves are almost universal on car tires, meaning you can often (carefully) inflate your bike tires with the air machines at roadside garages.

I don't think it would hurt to combine this one with its sibling answer
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Joe PhilllipsSep 6 '10 at 17:51

3

In the UK at least this can also be referred to as the 'car type' since it's common to our car tyres. It's quite useful to use this type of valve because it means you can get your tires pumped up at petrol stations.
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Colin NewellMar 3 '11 at 17:24

Pannier

A pannier, pronounced pan-yer /ˈpanyər, ˈpanēər/ (US) or pan-i-er /ˈpanɪə/
(UK) [1], is a bag designed to be mounted on the side of a bicycle rack. Bags can be made of nylon, canvas, or waterproof materials such as PVC. Rear is most common, but smaller panniers intended for a front rack are also available.

Often erroneously called a saddlebag because a pannier on a motorcycle or horse is attached to the saddle. On a bicycle, the saddlebag mounts behind the rider from loops at the back of the saddle. The saddle bag goes athwartship – from side to side.

Flip-Flop Hub

Most often seen on fixed gear track (velodrome) bikes, a flip flop hub is hub that allows a cog to be attached to each side.

This allows a rider of a fixed gear bike to effectively 'change' gears by taking the rear wheel off, flipping it around and reattaching the wheel.

Track riders will use this to have a smaller (more teeth, fewer gear inches) warmup gear that allows them to spin at a higher cadence and a larger (fewer teeth, more gear inches) cog for racing or high speed efforts.

Variations of flip-flop hubs might offer a freewheel in one direction and a fixed gear in the other, so a cyclist can convert the bike from a single-speed to a fixed gear bike by flipping the rear wheel around.

The unused cog is an additional hazard. Many velodromes require unused cogs to be removed. A collision involving a bike carrying an unused cog at the 2013 North America Harcourt Bicycle Polo Championships led to an amendment of the NAH ruleset to explicitly identify exposed unused cogs as a prohibited hazard. Players are permitted to carry an unused cog if it is covered.

For a fixed-gear road cyclist, a flip-flop hub often is used to allow one side as a fixed gear, and the other side to freewheel. This way, a tired fixie rider can switch to freewheeling (possibly with a different ratio) and get home.

The quickness of the release is defeated on most bikes by extra lugs that force you to unscrew the axle almost fully to remove the wheel. They are supposed to stop the wheel falling out if the release comes loose - but they are really to stop you sueing and so are called lawyer-lugs
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mgbOct 22 '10 at 3:51

Triathlon bars or Aerobars

Aerodynamic bike handlebars are for racing bicycles and particularly time trial bicycles.

Included are narrow, bolt-on extensions that draw the body forward into a tucked position, pursuit bars that spread the arms of the rider but drops the torso into a slightly lower position, and integrated units that combine elements of both designs.

Triathlon bars are commonly used in triathlons and time trial events on road and track. However, they are illegal in most mass start road races or any other event where drafting is permitted because, while aerodynamically advantageous, they tend to draw the hands away from brakes, make the rider slightly more unstable on the bike, and can be dangerous in the event of an accident. Further, they are not useful in sprints or shorter climbs where power is of greater importance than aerodynamics.

There is a distinct set of aerobars that are utilised in draft legal triathlons on regular road frames. As draft legal (ITU sanctioned) triathlon races require road frames that are UCI legal, a stubby pair of arms has been developed for this style of racing.

Tire Lever

aka Tire Iron

A tire lever is a small, narrow lever used to help lift a tire off a rim. Traditionally they were steel, later aluminium alloy and now most commonly they are plastic.

The most important feature of a tire lever is that it does not have any sharp edges that may "pinch" the tube (that is, become wedged between the tube and the tire) causing a small hole or tear in the tube.
Operation of tire levers usually involves either a pair or a triple set of levers. Levers can also be used help get a tire onto a rim when it is a particularly tight fit.

Stem

Attaches the handlebars to the bike, or, more precisely, to the steer tube (when using a threadless headset) or fork (when using a threaded headset). Many different sizes and angles of stems are available, so that the rider can place the handlebars where they will be the most comfortable during riding. There are also adjustable stems made, so the rider may change bar positions without removing the handlebars.

Chain Tool or Chain Breaker

Used to 'break' a chain by punching out one of the link pins. Needed to shorten a new chain to the correct length or to replace a broken link.

A chain link is placed in the open slot and the handle turned to force a punch pin into the pin of the chain, pushing it out of the other side.

Traditionally the tool needed to be used quite carefully such that the pin would not pushed all the way out, as the same pin was later used to reassemble the chain, using the same tool. Obviously, if a chain is repeatedly "broken" and reassembled this way at the same link the pin and associated holes in the plates will wear and no longer hold well, so care must be taken to not do this.

More recently this strategy has changed somewhat. Shimano now supplies special replacement pins which are equipped with a break-off guide cone on one end, making it easier to reassemble the chain. (Even with this scheme one should still avoid repeatedly "breaking" and reassembling the chain at the same link, though.)

Several other manufacturers now sell what is commonly called a master link (or quick link), which allows a chain to be reassembled without tools.

Chain Tug

AKA: Chain Tensioner

A device for use on bikes with horizontal dropouts, and normally with a fixed or single speed or hub gear. The chain tug(s) allow the chain tension and rear wheel alignment to be adjusted, and to stop the rear wheel from pulling forward while pedaling.

Some chain tugs are available with derailleur hangers to allow horizontal droput bikes to run derailleur gearing systems.

Bearing

A standard bicycle wheel bearing consists of an axle, a hub, two cones, two locknuts, and a number of steel balls. In both ends of the axle is a concave section known as the "cup" that the balls sit in. The "cone", threaded onto the axle, contacts the balls from the other side, and together the cup and cone retain the balls and serve as the surfaces against which the balls roll.

The locknut secures the cone so that it doesn't thread in or out as the hub turns relative to the (stationary) axle.

The bearings in the bottom bracket and headset are similar except that the cup part is stationary and the axle turns.

Derailleur hanger

The part of the bicycle frame that the rear derailleur screws into. It can be formed as part of the right rear dropout or can be a separate piece. Making the hanger a separate piece allows it to be made from a different alloy than the dropout and to be more precisely machined. Especially on inexpensive bikes, the separate hanger allows the same frame to be used in bikes with or without derailleurs.

On mountain bikes this arrangement is especially required because the derailleur is frequently exposed to hits from ground features and falls, and a hanger softer than the frame will bend first protecting both the frame and the derailleur, like an electrical fuse. This also allows for the hanger to be easily replaced, because frequent bends can lead to a fatigue fracture.

Often they are built into the frame like this (note that this bike is set up and singlespeed, with a derailleur in place you would never put the axle this far forward in the dropout):

I'm not sure I agree with the replacement ability not being a primary design point - for off road riding, it seems like this is key, especially on non-steel frames (e.g. aluminum), where the hanger cannot be safely bent back in cases of crashes due to metal fatigue.
–
BatmanMar 17 '14 at 7:02

Gear Inches

One of the several ways to describe gearing; how hard/easy the bike is to pedal. The actual figure is the equivalent diameter of the wheel if you were on a direct pedal cycle like a unicycle or an old fashioned high-wheeler. It does allow for different size wheels as well as the gears, but it ignores the effect of different crank lengths.

For example, a 700c tire is going to have a diameter of roughly 26.3" (depends on the width of the tire). If you have shifted to your smallest front ring of 24 teeth, and your biggest rear cog of 27 teeth then your gear inches are:

GI = (24/27)*26.3 = 23.4"

Note: if you want to take the math a little further - and of course I do since I am a math nut - you can find how far you travel each pedal stroke by remembering that:

Circumference = pi*Diameter

In our example:

Circumference = 3.14*23.4" = 73.5

Note: you can search for Bicycle Gear Calculator and find several pages online that will do the math for you. There will be a lot of variation and calculators use different rounding and make different assumptions about wheel width. Pre-prepared tables are available, calculated for ETRTO 23-622 (700c x 23mm) tyres or in the case of traditional track racers' tables, a "standard" wheel with an assumed 27" overall diameter.

Handlebars

The part of the bike you hold onto. When you turn the handlebars, the front wheel turns with them. The front wheel is held in the fork, which ends in a steerer tube, which in turn attaches to the stem, which clamps onto the handlebar.

Chainstay Length

A critical measurement used to help determine a proper chain length for any given bicycle. The chainstay length is measured from the center of the front chainring (centered on the bottom bracket spindle) to the center of the rear cog (centered on the rear axle).

Touring bicycles typically have longer chainstays to allow for more heel clearance when riding with panniers, but this comes at the cost of increased flex due to longer tubes. Bicycles designed for sprinting and for the track typically have extremely short chainstays.

Track pump (or floor pump)

A large pump that you use by standing on the bottom plate and moving the handle up and down. You can use both hands and your back to pump a high pressure tire quickly and easily. Generally for use at home - or at the track - rather than for carrying on the bike. Some manufacturers make portable track pumps which bolt to the down tube for easier inflation of high pressure tires.

Luggage Carrier

(a.k.a. Rack)

A luggage carrier, or rack, is a frame attached to a bicycle to provide space for a pannier or other back to be attached. They are frequently mounted over the rear wheel and are typically bolted to the bicycle and not easily removed.

Heavy-duty rear rack on a touring bike:

Reference:

Folding Bike

AKA Folder

A bike that's designed to fold down to a small package without disassembly. They usually have smaller wheels, and are designed to be taken on trains and buses. Many transit organizations that don't allow bikes during peak hours will allow folding bikes during these busy times. They also reduce storage space requirements, often useful in city apartments.

There are also bikes that do not fold, but are designed to be taken apart easily, with frame latches, quick-release latches, or hybrid folding/unlatching systems.

Hub Skewer

A replaceable part of a hub that attaches the hub/wheel assembly to the fork or frame. Some are equipped with a quick-release mechanism that allow removing the wheel without tools, facilitating changing a tire, putting a bike in the back seat of a car, etc. Unfortunately, the trade-off for easy wheel removal is that it's easier for thieves to remove a quick-release wheel.